DOUBLE SEATED BALANCED VALVE Russian patent published in 2000 - IPC

FIELD: pipe line fittings; control of flow of working medium. SUBSTANCE: in the course of operation valve changes its functional properties changing over from operation as double-seated valve to operation as single-seated valve with no change in balancing. Balancing of valve depends on interaction of shut-off member, stepped rod pressure of medium. Valve has body with branch pipes and with sliding bearing for rod seal. Mounted inside body is cylindrical holder with profiled ports on lateral surface and taper inner surface on which seats for shut-off member are formed. Holder is provided with cap with sliding bearing for rod and rod seal. Shut-off member is located inside holder. Shut-off member is connected with stepped rod and is made in form of plug having shape of truncated cone with through longitudinal holes. EFFECT: enhanced reliability due to balancing forces acting on shut-off member at any pressure and pressure drop at valve. 3 dwg